Woven wire belt for papermaking machines



Jan. 13,1942. H. G. SPECHT 2,269 8 9 WOVEN WIRE BELT FOR PAPER MAKING MACHINES Filed July 31, 1940 2 Sheets-Sheet l [lintill" 1! l ImlN NT R HQISRY Pam-1T.

ATTORNEY Jan. 13, 1942. H G gPEcHT 2,269,869

WOVEN WIRE BELT FOR PAPER MAKING MACHINES Filed July 31, 1940 2 Sheets-Sheet 2 .5. 1 wrVT TT &

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, H RRY El. spam-1 ATTORNEY Patented Jan. 13, 1942 WOVEN WIRE BELT FOR PAPERMAKING MACHINES Harry G. Specht, Montclair, N. J., assignor to Eastwood-Nealley Corporation, Belleville, N. J., a corporation of New Jersey Application July 31, 1940, Serial No. 348,814

7 Claims.

The present invention relates to woven wire belts particularly for paper making machines of the Fourdrinier type. These belts are in the form of a continuous band of fine wire mesh which moves over spaced supporting rolls and in contact with suction boxes and rolls, and it is desirable to provide a wire which will have a relatively long wearing life. The wire belt furthermore drives the paper machine from the couch roll, so that it must be capable of withstanding considerable longitudinal pulling strain. These wires are relatively expensive and in normal use have an average life of about twenty days. The cost of changing a wire is great due to lost time in production, so that any increase in the wearing life of the wire is worth a great deal to the paper mills. Another desirable object is to provide a wire having a relatively smooth top surface for the formation of the paper, so as to reduce wire marks as much as possible, while at the same time providing the necessary porosity to permit the water to drain through.

Attempts have been made heretofore to provide increased strength by increasing the size of the warp wires and also by weaving the warp wires in pairs, this two-in-the-dent arrangement having been carried out in plain weave in which the warp Wires are carried over and under single shute or weft wires. These have been objectionable due to the fact that it has not been possible with such weaves to provide the necessary crimp in the shute wires, so that in the paper formation side these shute wires would not come up into the plane of the warp, but would remain substantially straight, and therefore did not provide supporting points or knuckles for the paper stock substantially in the same plane and in cooperation with the supporting points or knuckles of the warp wires. As a result the paper formation surface of the wire produced wire marks in the paper, did not provide sufiicient support for the fibres, and allowed a considerable loss due to drainage of the fibres with the water.

It is an object of the present invention toprovide woven paper making wire in which the warp wires are woven in pairs, or two-in-the-dent arrangement, and to'weave such wires in twilled weave, wherein the warp wires are carried over one and under two shute wires, and whereby it becomes possible to increase the distance from the adjacent over-shute warp wire knuckles controlling and supporting the shute wires so that there is a sufiicient length of shute wire between the controlling warp wire knuckles to permit the shute wire to be crimped by the action of the reed of the wire weaving loom to bring the intermediate portions of the shute wire substantially into the plane of the warp wires at the paper formation side. This provides a two-in-the-clent weave, that is, two warp wires between or in the dent or space between the reed steels, in which a paper formation surface is provided which will ance in the dent of the reed between the sides of the reed steels and the warp wires, thereby greatly increasing the life of the reeds in the weaving operation, permitting the use of larger wire in a given mesh construction and adding to the life and strength of the wire, so that it can be used for longer runs and will efiectually withstand the strain of driving the paper machine from the couch roll. This woven wire construction, which permits of theme of thicker and stronger reed steels, furthermore permits the reeds to hit a harder blow in the loom, thereby greatly facilitating the crimping of the shute wires to provide the desired paper'formation surface, in which the crimped shute knuckles are substantially in the same plane as the warp knuckles to produce finished paper free from wire marks.

With the above and other objectsin view, embodiments of the invention are shown in the accompanying drawings, and these embodiments will be hereinafter more fully described with reference thereto, and the invention will be finally pointed out in the claims.

In the drawings:

Fig. 1 is an enlarged top plan view, from the paper formation side, of a portion of woven paper-making wire, according to one exemplary embodiment of the inventiomin which flat warp wires are employed and in which each of the warp wires of a pair extend over different shute wires.

Fig. 2 is a longitudinal sectional view, taken along the line- 2-2 of Fig. l. V

Fig. 3 is a transverse sectional view taken along the line 33 of Fig. 1.

Fig. 4 is a bottom plan view, from the wear side.

Fig. 5 is an enlarged diagrammatic plan view of a portion of the usual type of one-in-the-dent weave wire and showing the relation of the reed steels between the warp wires, and which beat up and crimp the shute wires in the weaving process in the loom.

Fig. 6 is a similar view showing the relation of the reed steels in the weaving of two-in-the-dent twill weave wire according to the invention, and in which the warp wires are of the same mesh number and warp wire width, as in the illustration shown in Fig. 5.

Fig. 7 is a similar view showing the two-in-thedent twill weave wire, according to the invention, and having the same mesh number as the wires illustrated in Figs. and 6, but in which the warp wires are of increased width.

Fig. 8 is an enlarged plan View of a modified form of woven wire, according to the invention, employing fiat warp wires in which both of the warp wires of a pair are carried over and under the same shute wires.

Fig. 9 is an enlarged plan view of a further modified form of the invention, in which the weave is similar to that illustrated in Figs. 1 to 4,

but in which the warp wires are of circular crosssection.

Fig. 10 is an enlarged plan view of still another modified form of the invention, in which the weave is similar to that illustrated in Fig. 8, but in which the warp wires are of circular crosssection.

Similar reference characters indicate corresponding parts throughout the several figures of the drawings.

Referring to the drawings and more particularly to Figs. 1 to 4, the Fourdrinier wire, according to the exemplary illustrated embodiment of the invention shown therein, comprises warp wires ID of flat rectangular cross-section, and shute or weft wires H of circular cross-section, the warp wires being arranged in pairs so that in the finished weave the Warp wires are in twoin-the-dent arrangement, that is, a pair of warp wires is arranged in the dent or space between adjacent reed steels of the weaving loom. The shute wires are interwoven with the warp wires in twill weave arrangement, that is, the warp wires extend over one and under two shute wires, and in this embodiment of the invention the two wires of each pair of warp wires are differentially interwoven with the shute wires, the over shute knuckles of one wa n wire being removed two shute wires from the over-shute knuckles of the other warp wire. This arrangement is continued across the weave, the next adjacent warp wire a of the next pair of warp wires having the overshute knuckles extending over the next removed shute Wire with respect to the over-shute knuckles of the adjacent warp wire of the first pair of warp wires.

The twill weave arrangement increases the lengths of the shute wires between the over-shute knuckles of the warp wires, which support or control the shute wires during weaving, there being at least two warp wires and at least one space between each pair of these con-trolling warp wire knuckles, and as distinguished from plain weave two-in-the-dent weave in which there is only one warp wire and one space between each pair of controlling warp wire knuckles, this spacing being insufficient to permit of adequate crimping of the length of shute wire therebetween. As a consequence this previously known two-in-thedent plain weave wire has been such that the shute wires remain substantially straight, so that they do not provide paper stock supporting knuckles in the plane of the upper surface of the wire as in the present invention, but produce wide recesses into which the fibres will be permitted to turn down.

According to the invention the shute wires are crimped by the action of the reed steels in the weaving loom to project paper supporting knuckles l2 upwardly substantially into the same plane as the paper supporting knuckles I3 of the warp wires. The reed marks produced by the heavy blow of the reed steels are indicated at M, these marks being upon the under or wear side of the woven wire and serving the function of increasing the drainage effect through the wire without in any way impairing the support of the paper stock by the warp and shute knuckles. It should be pointed out at this point that the method of weaving the woven wire belt of the invention, and in which the warp knuckles disposed at the upper side of the cloth may be referred to as over-shute shute-controlling warp knuckles, is a known procedure and is described for instance in my U. S. patent for Woven wire belt for papermaking machines, No. 2,003,124, dated May 28, 1935. It is understood from this known method that the warp wires control or predominate the weft wires in the weaving of the wire cloth, and for this purpose the warp wires have greater tensile strength. The weft wires, which are shaped by and follow the action of the warp wires, only indirectly take the strain imposed by the beating up action of the reed, and should not be such as to overcome the predominance or control of the warp wires. The disposition of the reed marks at the underside of the weft wires is brought about by a known procedure in the weaving of wire cloth and is described for instance in my U. S. patent for Woven wire belt for papermaking machines, No. 2,122,592, dated July 5, 1938. In the weaving operation the reed hits the weft wires between the warp wires and produces a reed mark, which in practice is produced at a point about 60 to removed from the position at the underside of u the weft as shown in Figs. 3 and 4, the tension applied to the warp, which is greater at one side of the shed than at the other side, causing the weft wires to turn about 60 to 90 bringing the reed mark to the underside of the fabric. The action of the reed steels also tends to slightly imbed the warp knuckles at the upper side of the woven wire where they cross over the weft wires into the shute wires to a slight degree, which has the effect of producing an interlocking relation which prevents sleaziness in the wire. The drainage effect of the Wire is further increased due to the fact that in addition to direct drainage through the mesh openings the two-in-the-dent weaving creates side drainage downwardly from the warp and shute knuckles, due to the arrangement shown in Figs. 1 to 4 in which each overshute knuckle of each of the warp wires of each pair has an under-shute portion of the other warp wire of the pair arranged adjacent to it, and whereby side drain passages are provided between the two adjacent warp wires of each pair of warp wires where the warp wires incline downwardly from the over-shute knuckles to the under-shute portions. The drainage effect produced by this arrangement of the inclined surfaces of the over-shute knuckles and under-shute portions of the warp wires is due to capillary action assisted by the suction produced in the suction boxes over which the wire belt moves. The arrangement of the surfaces furthermore provides termining either wire or reed steel size, is to dishort bridging spaces between the projected warp and weft knuckles which provides adequate support for the paper fibres so that they do not tend to wash down through the mesh openings.

In the weaving of Fourdrinier wire the reed maker requires that the reed steel be of a certain thickness for strength, and in practice do not like to makethe reed steel less than from .005 to .006 in thickness, in order to have the reed stand up in mechanical operation. Also the dent or space between adjacent reed steels must be sufliciently wider than the width of the warp wires between the reed steels so that there is a clearance between the sides of the reed. steel and the adjacent surfaces of the warp wires, this clearance usually amounting to approximately .001. The thickness of the reed steel plus the clearance between the warp wires and the steel represents the open area in the woven wires.

Comparing the weaves shown in Figs. 5, 6 and '7, it will be seen that in Fig. 5, which illustrates the ordinary one-in-the-dent weave, a reed steel I is arranged between each warp wire and clearance spaces are provided between the sides of the reed steel and the adjacent warp wires. Assume that this is a 60 mesh wire, that is, 60 warp wires to the inch, and that the approximate Width of the warp wires is .0095, this being the largest width warp wire that can be woven practically in a 60 mesh wire, having regard for the minimum size of the reed steel and the necessary clearance spaces. In this case the total available space for each warp wire and reed steel, that is, the space indicated in Fig. 5 by the arrow pointed line between the left hand edges of the adjacent warp wires is .0166. Deducting the summation of the .0095 warp Wire and .001 for clearance, or .0105, from the available space of .0166, the indicated thickness of th'e reed steel is .006. Thus it will be seen that in this 60 mesh wire any larger width warp wires would not only decrease the drainage area but would necessitate the use of a very thin reed steel, which as above pointed out is objectionable and impracticable. In weaving the 60 mesh two-in-the-dent wire as shown in Fig. 6, the warp wires are shown for direct comparison purposes as of the same size as those in Fig. 5, that is, .0095. In this case however, the reed space is between adjacent pairs of warp wires and while still providing .001 clearance permits the use of a reed having a thickness of approximately twice that shown in Fig. 5, plus the amount of the clearanceof the extra reed steel employed in Fig. 5, or .013, the direct drainage area remaining approximately the same. As shown in Fig. '7, the same 60 mesh wire may now be woven with its warp wire of substantially greater width than is permitted in the weave shown in Fig. 5, for instance, the warp wires may be .010 or .011, at the same time the reed steel width will be substantially greater than the .006 reed width shown in Fig. 5. The reduction in the direct drainage area is compensated for and the paper supporting and drainage action improved by the additional side drainage brought about by the two-in-the dent crimped shute twill weave according to th'e invention. In this way considerably greater tensile strength may be obtained in the woven wire through the use of larger warp wires, and at the same time the reed steels may be made sufficiently heavy so that they may hit a harder blow in the loom thereby facilitating crimping of the shute.

In any given mesh construction the procedure to be followed, according to the invention in devide the number of mesh construction into one inch, securing the total space available for the wire, the clearance, and the reed steel. Working from this as a base and by using the two-in-thedent weave, it is not only possible to add to the diameter of the wire the space requiredby the reed steel when a single warp or one-in-the-dent weave is used, without appreciable reduction in direct drainage area, but it is also possible to substantially increase the thickness of the reed steel, thus enabling the production of a wire of increased strength and efiiciency. Also the making of the reed steels is simplified, and their life in operation in the loom is increased, thereby effecting substantial savings in the production costs of the woven wire.

The two-in-the-dent warp wires, in cooperation with the crimped knuckles of the shute wires, provides increased support for the paper forming fibres, effectually holding them in the sheet without the tendency to turn down into the drainage passages, thus making for a stronger and smoother paper sheet and decreasing waste through drainage of the fibres through the wire with the water. This is especially true and important in connection with the fines as they are knownin the paper making industry, representing the small fibres that go into th'e making of a paper sheet.

In Fig. 8 I have illustrated a modified form of the invention, in which both of the wires of the two-in-thedent warp wires [0 are woven' to-v gether, that is, both wires are carried over and under the same shute wires.

In Fig. 9 I have illustrated another modified form of the invention, in which the weave is similar to that illustrated in Figs 1 to 4, but in which the warp wires Ill are of circular crosssection.

In Fig. 10 I have illustrated still another modified form of the invention, in which the weave is similar to that illustrated in Fig. 8, but in which the warp wires Ill are of circular cross-section.

I have illustrated and described preferred and satisfactory embodiments of the invention, but it will be understood that changes may be made therein, within the spirit and scope thereof, as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. Woven wire fabric for paper making machines, comprising interwoven warp and shute wires with knuckles produced in both the Warp and shute wires, the shute wires having spaced reed marks at their undersides, the warp wires being arranged in pairs and interwoven with the shute wires with each pair disposed between two adjacent reed marks of each of said shute wires and the warp wires being individually interwoven with the shute wires in twill weave arrangement in which the warp wires each extend over one and under a plurality of shute wires in the warp direction of the fabric, there being in the shute direction of the fabric at least two under shute warp wire portions and at least one mesh opening between transversely adjacent over-shute warp knuckles extending over the same shute wire, and in the warp direction at least two overwarp shute knuckles between longitudinally adjacent over-shute warp knuckles, and the shute wires being crimped upwardly between said overshute warp wire knuckles substantially into the plane of the upper surface of said over-shute warp wire knuckles.

characterized in that said warp wires are of circular cross-section.

6. The invention as defined in claim 1, further characterized in that said warp wires are of fiat substantially oblong cross-section and said shute wires are of circular cross-section.

7. The invention as defined in claim 1, further characterized in that said warp wires are of circular cross-section and said shute wires are of 10 circular cross-section.

HARRY G. SPECHT. 

